On the cover of the Flaming Lips’ most recent album, “At War With the Mystics,” a small figure stands with outstretched arms at the mercy of an erupting volcano. Perhaps this scene is an intended parallel to the overwhelmingly epic history of this celebrated band: Over a period spanning well over two decades, the Lips have released 11 albums and one compilation, producing extraordinary experimental songs that, regardless of music trends, never cease to produce generations of Flaming Lips devotees. Although the Lips’ newest album will undoubtedly lure fans to a similar obsession, “At War With the Mystics” fails to achieve a distinction as explosive as their past works.

With a reputation for innovation, the Lips could only be expected to produce another stunning album, especially after a four-year hiatus following their last release, in 2002. Indeed, “At War” follows the band’s trend of originality by introducing a playful, pop-influenced album backed by a solid rock base — an unexpected (and overall incoherent) combination. However true to their spirit of reinvention, the Lips have possibly strayed too far. Although sporting the ever-present themes of love, life and death, the album’s lighthearted, often silly sounds and simple lyrics are ultimately disappointing.

The first track, “Yeah Yeah Yeah Song,” is a perfect example of the frivolousness that takes away from the album’s potential for greatness. Despite the political theme of power placed in the wrong hands, the song boasts an upbeat, pop sound. Riding on an uncomplicated melody, the track sets a tone of silly experimentation for the remainder of the album with bubbly vocals reaching cringe-worthy highs and ridiculous lows.

These playful themes, although by no means as compelling, are a refreshing change from the Lips’ past songs of profundity. With Prince-like vocals and catchy lyrics, the album’s following song, “Free Radicals,” is an irresistible sing-along track: “You think you’re radical/ but you’re not so radical/ you’re fanatical,” reminiscent of Spoon’s “I Turn My Camera On.” Unlike typical pop songs, “Free Radicals” rests on a core of rock guitar and strong percussion, an interesting juxtaposition to the track’s added studio production.

Yet sugarcoated tunes, crude melodies and simple lyrics are only so engaging. “At War” begins with a promising new sound, but fails to maintain interest by focusing on experimental ornamentation rather than captivating simplicity. Songs such like “My Cosmic Autumn Rebellion” and “Mr. Ambulance Driver” are pleasing at most, yet descend into unoriginal, ebullient patterns that quickly border on boring. The distant, fuzzy vocals on these tracks are fortunately compensated by strong percussion, a sturdy support running through the entire album.

“At War,” typical of the Flaming Lips, does not fail to surprise. In between experimental songs that sacrifice poignancy for goofy are tracks that stand out as polished accomplishments backed by intriguing lyrics. The album’s fifth track, “Vein of Stars,” focuses on the basics of music, relying on a cool piano tune and minimal guitar to let the gently resonant lyrics shine through. As singer Wayne Coyne contemplates the complexities of the universe and questions life (“Who knows, maybe there isn’t/ a vein of stars calling out my name”), listeners will inevitably fall into a similar serene state.

A highlight of “At War” is the penultimate track, interestingly, musician Steven Drozd’s singing debut. The song, “Pompeii Am Götterdämmerung,” is an instant rock classic, recalling Pink Floyd’s guitar riffs and Led Zeppelin’s heavy drums. Yet the song maintains a quiet delicacy as Drozd’s ethereal vocals glide over the muted music, becoming the perfect blend of blithe sound and weighty rock — a difficult combination to master.

Although “At War” is a fine compilation of experimental sound, fusing the modern and bubbly with classic rock and roll, the album is an unfortunate departure from the Flaming Lips’ previous phenomenal albums. While an example of their ability to embrace the unusual — a skill that has allowed the band to survive for over 20 years — “At War With the Mystics” brings unprecedented dissatisfaction to an epic era of great music.